Last updated: June 15, 2025

Ampere hours to watt hours (Ah to Wh) calculator

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Definitions

What is Ah?

Ampere-hour or Amp-hour has a symbol of A h, A⋅h, or Ah, which is the measurement of total energy charge in a power source that can produce one ampere (1A) of current to a circuit for one hour (1h).

Two Rechargeable AAA Batteries
Rechargeable AAA battery rated at 900 mAh

Example: A rechargeable AAA battery with a capacity rating of 900 mAh can produce

  • Or 500 milliamps (500 mA) of current for 1.8 hours.
  • One ampere (1A) of current for 0.9 hours.

What is Wh?

A watt-hour is a unit of electrical energy measurement equivalent to a power consumption of one watt for one hour. It has a unit symbol of W⋅h or Wh which is often found on small batteries to help you determine how long it can power the equipment or devices based on their power rating in watts.

Google Pixel 4 Battery Rated at 10.78 Wh or 2,800 mAh
Google Pixel 4 battery rate at 10.78 Wh or 2,800 mAh

Example: A Li-ion polymer battery inside a Google Pixel 4 phone has a capacity of 2,800 milliamp-hours or 10.78 watt-hours. Theoretically, the battery could power:

  • A one-watt LED bulb for 10.78 hours.
  • A five-watt light bulb for 2.156 hours.
  • A ten-watt portable mini fan for 1.078 hours.

Ah to Wh Formula

The formula to convert an energy value from ampere-hours to watt-hours is Wh = Ah x V.

$$\text{Energy in Wh} = \frac{\text{Energy in Ah} \times \text{Voltage}}{1,000}$$

Or

$${Wh} = \frac{{Ah} \times {V}}{1,000}$$

Where Ah is the energy value in amp-hours, V is the voltage of the energy source, and Wh is the equivalent energy value in watt-hours.

How to convert amp-hour to watt-hour?

To convert energy value from amp-hours to watt-hours or Ah to Wh, follow the simple steps below:

  1. Write down the energy value in amp-hours (Ah).
  2. Multiply it by the value of the energy source voltage (V).
  3. The result from the equation is the value of an energy value in watt-hours (Wh).

Example: Find the maximum energy that can be produced by a 12V battery

What is the maximum energy can a 12V battery rated at 100Ah generates in Wh? Assuming it can use 100% of its capacity.

To find the maximum generated energy by the battery in watt-hours or Wh, use the following formula and follows by entering the given values.

$\text{Energy in Wh} = \text{Energy in Ah} \times \text{Voltage}$
$\text{Energy in Wh} = {100\ Ah} \times {12\ V}$

Therefore,

$\text{Energy in Wh} = {1,200\ Wh}$

So, the maximum energy generated by a 12V battery with a capacity rated at 100Ah is 1,200 Wh.

Typical Ah to Wh Conversion Table

Here is the conversion table from amp-hours (Ah) to watt-hours (Wh) for typical voltage sources. Use the table for a quick reference and remember it for everyday use.

1.2V NiMH rechargeable battery

Ampere-hour (Ah)Voltage (V)Watt-hour (Wh)
0.1 Ah1.2 V0.12 Wh
0.5 Ah1.2 V0.60 Wh
1 Ah1.2 V1.20 Wh
2 Ah1.2 V2.40 Wh
3 Ah1.2 V3.60 Wh
4 Ah1.2 V4.80 Wh
5 Ah1.2 V6.00 Wh
6 Ah1.2 V7.20 Wh
7 Ah1.2 V8.40 Wh
8 Ah1.2 V9.60 Wh
9 Ah1.2 V10.80 Wh
10 Ah1.2 V12.00 Wh

1.5V Alkaline battery

Ampere-hour (Ah)Voltage (V)Watt-hour (Wh)
0.1 Ah1.5 V0.15 Wh
0.5 Ah1.5 V0.75 Wh
1 Ah1.5 V1.50 Wh
2 Ah1.5 V3.00 Wh
3 Ah1.5 V4.50 Wh
4 Ah1.5 V6.00 Wh
5 Ah1.5 V7.50 Wh
6 Ah1.5 V9.00 Wh
7 Ah1.5 V10.50 Wh
8 Ah1.5 V12.00 Wh
9 Ah1.5 V13.50 Wh
10 Ah1.5 V15.00 Wh

3.6V 18650 rechargeable battery

Ampere-hour (Ah)Voltage (V)Watt-hour (Wh)
0.1 Ah3.6 V0.36 Wh
0.5 Ah3.6 V1.80 Wh
1 Ah3.6 V3.60 Wh
2 Ah3.6 V7.20 Wh
3 Ah3.6 V10.80 Wh
4 Ah3.6 V14.40 Wh
5 Ah3.6 V18.00 Wh
6 Ah3.6 V21.60 Wh
7 Ah3.6 V25.20 Wh
8 Ah3.6 V28.80 Wh
9 Ah3.6 V32.40 Wh
10 Ah3.6 V36.00 Wh

FAQs

How many watt hours in an amp-hour?

For typical 12V car or solar batteries, one amp-hour (1 Ah) equivalence to 12 watt-hours (12 Wh).

VoltageAmp hourWatt-hour
1.2 V1 Ah1.2 Wh
1.5 V1 Ah1.5 Wh
3.6 V1 Ah3.6 Wh
9 V1 Ah9 Wh
12 V1 Ah12 Wh
24 V1 Ah24 Wh
48 V1 Ah48 Wh
Table of the number of watt-hours in an amp-hour in different battery voltages.

Ah to Wh Calculator

About this app

Ah to Wh Calculator

Quickly convert amp-hours (Ah) to watt-hours (Wh) with our calculator app. We will also show you the conversion formula and examples.

Availability

You can use the calculator for free as a PWA web app online or install it locally on any modern operating system, including Android, iOS, Windows 11/10, and macOS.

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